DES Moms More Likely to Have Gay or Bi Daughters, Study Says

Dan Fagin, Newsday

Published
4:00 am PST, Wednesday, February 1, 1995

1995-02-01 04:00:00 PDT New York -- Women who took the synthetic estrogen DES when pregnant were more likely to have daughters with bisexual or homosexual tendencies, according to a newly published study by a Columbia University psychologist.

Experts said the finding had important implications for two closely related -- and hotly debated -- current controversies in science: Does biology play a major role in determining sexual orientation? And, are estrogen-mimicking man-made chemicals having powerful effects on people?

"This is potentially a very significant finding," said Bruce McEwen, director of the laboratory of neural endocrinology at Rockefeller University in Manhattan and an expert on hormonal effects on the brain. "This really is a bold hypothesis, but it is a credible hypothesis."

Researchers found that eight of the 117 DES daughters studied had bisexual or homosexual tendencies, while none did in a carefully selected 117-woman control group.

'STATISTICALLY SIGNIFICANT

"It is a mild increase, but it is statistically significant, and it was repeated in all the subgroups we studied," said the study's lead author, Dr. Heino Meyer-Bahlburg, a professor of clinical psychology at the College of Physicians & Surgeons of Columbia University. The research was reported in the January edition of the journal Developmental Psychology.

Women who were exposed to DES in their mothers' wombs were compared to their unexposed sisters, to unexposed women with gynecological problems similar to those caused by DES, and to a healthy control group. In each case, psychological tests developed by sex researcher Alfred Kinsey showed that the DES women were significantly more likely to have homosexual or bisexual tendencies, according to the Columbia study.

The results suggest that while exposure to estrogenic chemicals in the womb is not the dominant cause of homosexuality, it may be one of many causes -- some inborn and some learned, Meyer-Bahlburg said.

DES, or diethylstilbestrol, was widely prescribed to pregnant women as an anti-miscarriage drug for more than 20 years, until it was banned in 1971 for causing vaginal and cervical cancers in female offspring, among other health problems.

It is considered too dangerous today to give people similarly huge doses of estrogenic hormones, so studying DES sons and daughters is the only way to determine the effects of powerful estrogens on human development.

Several gay groups declined to comment on the Columbia study.

While some lesbians may welcome evidence that sexual orientation is not a matter of choice, others may fear that the information will be misused. "The fear is that this could have some sinister intent, that it is going to be aimed at curing or diagnosing (homosexuality), and that is offensive to the community," said Diane Salvatore, a New Jersey author of several books of lesbian fiction.

DIFFERENT STORY ON DES SONS

Meyer-Bahlburg also has studied DES sons and found no increase in homosexuality or bisexuality.

But the increase among DES daughters is consistent with what researchers know about the fetal brain, experts said.

"It's kind of a neat finding because it confirms what animal research has shown" -- that it is estrogen that masculinizes the brain even though this hormone is more commonly associated with female biology, said Barbara Sherwin, an expert on prenatal hormones and a professor of psychology at McGill University in Montreal.

Some scientists say the brains of female fetuses, unlike male ones, have mechanisms that block actions of some natural estrogens. But DES and other man-made estrogens have distinctive chemical characteristics that allow them to bypass usual controls on development. They enter the fetal brain more freely and, the new work suggests, trigger a process of masculinization that influences sexual preference.

Still unknown is whether other man-made estrogenic chemicals could be having similar effects.